She Came Through a Rift in Time and Space

The heroine is utterly baffled: "What is a heart?"

The hero grins cheekily: "Why don't I feel around and show you?"

The heroine spreads her arms: "Sure."

The hero is instantly flustered and says with a hint of menace, "From now on, nobody else is allowed to touch your chest. If anyone even thinks about it, I'll smash his head in..."

A few seconds later...

The hero sees stars as blood spurts from his nose. "Sis, why did you hit me again?"

The heroine looks completely innocent. "You told me to."

A bizarre pairing of a straight-laced girl and a sharp-tongued softie.